The use of a filled plastic composition for manufacturing functional components is known from the prior art. Such compositions typically comprise a plastic matrix and a filler material.
A high amount of filler material is desirable to improve some properties of such functional components. An increasing amount of filler material can, for example, produce an increase or a greater value of the thermal conductivity, of the density, of the magnetic properties, or of the screening effect with respect to electromagnetic signals and ionizing radiation. A great improvement of some properties can in particular be observed when the amount of filler material is close to the theoretical maximum since the number of particle contacts increases greatly in this range. It is possible to speak of a proximity to the theoretical maximum when the volume fraction of the filler material comes close to the volume fraction of the native filler material particles with a maximum packing density. The volume fraction of the native filler material particles at a maximum packing density results directly from the particle size distribution.
On the other hand, as the amount of filler material increases, the melt viscosity of the plastic compositions also rises, whereby high-filled compositions of this type are not accessible to every processing technology. Whereas molding compounds and casting compounds can be highly loaded with filler material in part at the cost of design freedom, highly filled plastic compositions are often not suitable for a processing within the framework of a variable injection molding process or extrusion process. Furthermore, some mechanical properties of the components are degraded by a high amount of filler material and the highly filled components tend to be brittle.
It is the object of the invention to provide plastic compositions that are as highly filled as possible that can be processed within the framework of an injection molding process or extrusion process and that additionally have acceptable mechanical properties.